Answer:
kinetic energy of the train = 2,910.6 x 10⁷ joule
Explanation:
Given:
Mass of train = 3.3 x 10⁷ kg
Speed of train = 42 m/s
Find:
kinetic energy of the train
Computation:
kinetic energy = (1/2)(m)(v²)
kinetic energy of the train = (1/2)(3.3 x 10⁷)(42²)
kinetic energy of the train = (1/2)(3.3 x 10⁷)(1,764)
kinetic energy of the train = (3.3 x 10⁷)(882)
kinetic energy of the train = 2,910.6 x 10⁷ joule
You need the kinematic equation for distance as a function of acceleration:
![d = [v(initial) *t] + 0.5a*t^{2}](https://tex.z-dn.net/?f=d%20%3D%20%5Bv%28initial%29%20%2At%5D%20%2B%200.5a%2At%5E%7B2%7D)
where a = gravitational acceleration 9.8m/s^{2}
v(initial) = starting velocity
t = time of fall
if the stone started at rest then v(initial) = 0 making the equation simply
Let me know if you still need further help :)
Answer:
51 mph
Explanation:
Given: A certain aircraft can fly 612 miles with the wind in 3 hours and travel the same distance against the wind in 6 hours.
Formula: 
Let speed of aircraft be x mph and speed of wind y mph
Aircraft along wind:
Actual speed of aircraft = x + y
Time taken = 3 hours
Distance = 612 miles
Aircraft against wind:
Actual speed of aircraft = x - y
Time taken = 6 hours
Distance = 612 miles
By solving equation (1) and equation (2) and we get
x = 153 mph
y = 51 mph
Hence, The speed of wind will be 51 mph
Answer:
a. 78 degree
Explanation:
According to Snell's Law, we have:
(ni)(Sin θi) = (nr)(Sin θr)
where,
ni = Refractive index of medium on which light is incident
ni = Refractive index of ethyl alcohol = 1.361
nr = Refractive index of medium from which light is refracted
nr = Refractive index of ethyl alcohol = 1.333
θi = Angle of Incidence
θr = Angle of refraction
So, the Angle of Incidence is know as the Critical Angle (θc), when the refracted angle becomes 90°. This is the case of total internal reflection. That is:
θi = θc
when, θr = 90°
Therefore, Snell's Law becomes:
(1.361)(Sin θc) = (1.333)(Sin 90°)
Sin θc = 1.333/1.361
θc = Sin⁻¹ (0.9794)
θc = 78.35° = 78° (Approximately)
Therefore, correct answer will be:
a. <u>78 degree</u>
Answer:
The object will contine to fall, but at a constant velocity. There will be no more acceleration.
Explanation: When the force of gravity is equal to the reverse force of air resistance, there will will be no net force on the falling obect. F = ma, and F (net) = 0. It will continue at the same speed until those forces become imbalanced again (such as when the force pushing up from the ground is greater than the force of gravity pulling it down). The metric term for this sudden resistance is "crash/bang/clunk/yieouch."
